package com.xju.filter;

import javax.servlet.*;
import javax.servlet.annotation.WebFilter;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;

@WebFilter("/*") // 使用注解配置过滤器，匹配所有请求
public class CorsFilter implements Filter {

    @Override
    public void doFilter(ServletRequest req, ServletResponse res, FilterChain chain) throws IOException, ServletException {
        HttpServletResponse response = (HttpServletResponse) res;
        HttpServletRequest request = (HttpServletRequest) req;

        // 添加允许访问的来源、方法和头部信息
        response.setHeader("Access-Control-Allow-Origin", "*");  // 根据需求调整
        response.setHeader("Access-Control-Allow-Methods", "GET, POST, PUT, DELETE, OPTIONS");
        response.setHeader("Access-Control-Allow-Headers", "Content-Type, Authorization");

        // 如果是预检请求(options)，直接返回200状态码
        if ("OPTIONS".equalsIgnoreCase(request.getMethod())) {
            response.setStatus(HttpServletResponse.SC_OK);
            return;
        }

        chain.doFilter(req, res);
    }

    @Override
    public void init(FilterConfig filterConfig) {}

    @Override
    public void destroy() {}
}